1. Technical Field
The present invention relates to a sample cell for containing a sample for fluorescent X-ray analysis, and an instrument for assembling the sample cell and, more specifically relates to a sample cell for fluorescent X-ray analysis for containing a volatile sample in a sealed state, and a sample cell assembly instrument for assembling the sample cell for fluorescent X-ray analysis.
2. Description of Related Art
Fluorescent X-ray analysis is an analysis method in which a sample is irradiated with a primary X-ray, a fluorescent X-ray generated from the sample is detected, and qualitative analysis or quantitative analysis of an element contained in the sample is performed on the basis of a spectrum of the fluorescent X-ray. A fluorescent X-ray analyzer for performing the fluorescent X-ray analysis includes an X-ray tube that generates the primary X-ray, an X-ray detector in which a semiconductor detection device or a proportional counter tube is used, and an analyzer that analyzes a wavelength distribution or an energy distribution of an X-ray detected by the X-ray detector. When the fluorescent X-ray analysis is performed, the sample is irradiated with the primary X-ray generated by the X-ray tube, the fluorescent X-ray generated from the sample irradiated with the primary X-ray is detected by the X-ray detector, and the spectrum of the detected fluorescent X-ray is analyzed by the analyzer.
It is possible to utilize such fluorescent X-ray analysis for element analysis of a fluid sample. For example, for the purpose of reducing a hazardous component contained in a liquid fuel such as light oil or the like, the element analysis of the liquid fuel utilizing the fluorescent X-ray analysis is performed. Japanese Patent Application Laid-Open No. 09-127028 describes a fluorescent X-ray analyzer that performs fluorescent X-ray analysis of a fluid sample. When a volatile sample such as the liquid fuel or the like is analyzed, the sample is contained inside a sealed sample cell in order to prevent a reduction or deterioration of the sample resulting from its volatilization. Japanese Patent Application Laid-Open No. 09-127028 describes a technique in which a fluid sample is contained inside a sample cell of which one surface is sealed with an X-ray transmission sheet that allows transmission of the X-ray, the sample inside the sample cell is irradiated with the primary X-ray through the X-ray transmission sheet serving as the bottom surface of the sample cell, and the fluorescent X-ray emitted through the X-ray transmission sheet is detected. In addition, Japanese Patent Application Laid-Open No. 07-134082 describes a sample cell in which a fluid sample is enclosed between two sheets.
Further, Japanese Unexamined Patent Application Laid-Open No. 09-257674 discloses a sample cell that contains a fluid sample. The sample cell includes a sample cup, an X-ray transmission sheet that allows transmission of the X-ray, and an outer frame that externally fits on the sample cup. When the sample cell is assembled, the fluid sample is injected into the sample cup having an upper surface serving as an opening portion, the X-ray transmission sheet is placed on the upper surface of the sample cup, and the outer frame is fitted on the sample cup from the upper side of the sample cup such that the outer frame is externally fitted on the sample cup with the X-ray transmission sheet interposed therebetween. The X-ray transmission sheet is pulled from its center in a radial direction when the outer frame is fitted, and a circumferential portion thereof is interposed between the outer circumference of the sample cup and the outer frame, whereby the X-ray transmission sheet is disposed in tension so as to seal the opening portion of the sample cup. When the fluorescent X-ray analysis is performed, the X-ray transmission sheet is used as the bottom surface of the sample cell, the sample inside the sample cell is irradiated with the primary X-ray through the X-ray transmission sheet, and the fluorescent X-ray emitted through the X-ray transmission sheet is detected.